On Fox News Channel’s “Hannity” on Tuesday night, former New York City Police Department detective Bo Dietl explained why the “Knockout” game — an activity which involves sucker-punching an unsuspecting bystander with the goal of knocking them unconscious — is something the news media should be devoting more attention to, despite its racial aspects.

According to Dietl, the media has largely ignored the trend because it involves black-on-white crime...